Abstract

Micro‐scale mechanical devices continue to be of interest in a broad range of sensor and device applications. Many fundamental issues pertaining to the operation and performance of these devices remain to be thoroughly investigated. This is especially true in the recently developed field of nanoelectromechanical systems(NEMS). Resonant devices are now being produced in single‐crystal silicon with released features as small as 30 nm. Besides novel device applications these structures may be used to explore fundamental properties and mechanisms that include internal friction as a function of scale. Measurements and analysis are reported here that, for the first time, characterize the detailed vibratory response of micro‐scale oscillators (∼100 μm). The devices are placed in a vacuum chamber, excited inertially, and measured optically with a laser Doppler vibrometer (LDV) instrument. Single‐point swept frequency measurements are used to investigate the vibrational spectrum of the oscillators and determine the Q. Spatial scans allow for mode identification and help to identify energy loss mechanisms into the supporting structure. In addition to observing the fundamental torsional and translational modes, we also observe numerous flexural modes of the devices. Both linear and nonlinear behavior are observed. [Work supported by ONR.]